Elongated projectile-shell for smooth-bore guns



T. E. MURRAY.JR., AND J. B. MURRAY.

ELONGATED PROJECTILE SHELL FOR SMOOTH BORE GUNS.

APPLICATION FILED OCT. 25. 1918.

1,310,129. Patented July 15, 1919.

' shell for smooth bore guns.

UNITED STATES PATENT OFFICE. I

THOMAS n MURRAY, JR, AND Josnrn re. MURRAY, or BnooKLYn, new YORK.

ELONG-ATED PROJECTILE-SHELL FOR SMOOTH-BORE GUNS.

Specification of Letters Patent. Patented July 15, 1919.

Application filed October 25, 1918. Serial No. 259,622.

To all whom it may concern:

Be it known that we, THoMAs E. MURRAY, Jr., and JOSEPH B. MURRAY, citizens of the United States, residing at Brooklyn, in the county of Kings and State of New York, have invented a certainnew and useful Improvement in Elongated Projectile-Shells for Smooth-Bore Guns, of which the following is a specification.

The invention is an elongated projectile It is herein illustrated in a trench bomb adapted to be thrown from a trench mortar. The particular type of bomb shown is one made of struck up sheet metal in two interchangeable half sections electrically welded at their registering edges. Such projectiles are very rapidly made and with the minimum of labor and expense; It is necessary, however, in order to avoid inaccuracies of flight that they should fit the bore of the gun. On the other hand, when they are produced from sheet metal and involve electrical welding and rapid manufacture, slight inaccuracies of form may occur which require a truing of the projectile after it is completed. If thls truing isdone by machining, as in the lathe,

and over the whole cylindrlcal periphery o the projectile, to make that whole periphery fit the-bore, then inaccuracies are likely to result from that manipulation, which'besides adds much-to the expense of manufacture.

By our invention the projectile periphery which fits the bore is reduced to a rib or a plurality of ribs which surround the shell body and are so located or constructed that the projectile will be properly positioned with its longitudinal axis in the longitudinal axis of the bore'and supported so that it cannot tilt therein. To true simply a rib or even a plurality of narrow ribs is a much easier and less costly operation than to true the whole cylindrical surface of the shell, while for guiding purposes a rib (or ribs) is quite as efiicient as the said entire surface-the projectile being also rendered lighter so that it requires less metal and is more easily handled.

In the accompanying drawings\ Figure 1 is a longitudinal section of our projectile shell having two guide ribs. Fig. 2 is a similar view of our projectile shell having three guide ribs and disposed in a smoothbore gun. Fig. 3 is asimilar view of our projectile shell having one guide rib and modified in form as hereinafter exof Fig. 3.

Similar letters of reference indicate like parts. V As here shown, the shell of elongated form 1sstruck up from sheetmetal in two longitudinal interchangeable sections A, B, each section having a body portion C, end walls D, E and on said body portion a rib F or a plurality of ribs, as hereafter explained. In the end wall D is the flanged opening G for the reception of the usual fuse and receptacle containing the exploding charge, not here shown. The longitudinal straight edges of the sections A, B are placed in registering contact andelectrically welded, so that the shell becomes integral with one or more oncircling struck up ribs. In Fig. 1 are shown tw such ribs H, I adjacent to the end walls D, E. In Fig.1.? the shell is shown with three similar ribs I, J, the rib J being located between the ribs H, I. In Fig. 3 a single rib F is shown, the shape of the shell being tapering, as shown at K, from said rib to the.

plained. Fig. 4 is a section on the line 4, 4 of Flg. 1. Flg. 5 is a section on the line 5, 5

or surfaces of the rib or ribs are required to be made truly circular. This is of conslderable economical importance, since when the shell sectionsare rapidly struck up from sheet metalin dies and afterward electrically welded as described, any slight eccentricities or other departures from a truly circular cross section which may occur require to be corrected in, order to insure accuracy in flight. If the entire circumferential periphery of the shell is in contact with the bore surface, then it is obvious that the correction or truing must take place over that whole periphery. If, for example, this is done by machining in the lathe, possible errors due to inexact centering may result. On the other hand, if thecircumferential contact area is reduced to that of a rib or .ribs, then the truing operation, if needed at all, is much more easily and accurately performed.

weight of We have stated that a single rib may be used, but this involves some further considerations. Such a single rib might be the middle rib J of Fig. 2, the outer ribs H, I being omitted. In such event, however, the the portions of the projectile on opposite sides of the rib should be made as nearly equal as possible in order to prevent any tilting on the rib as a fulcrum, and a consequent inaccuracy of flight. It is, therefore, preferable in the case of a single rib to widen the same, as shown at F, Fig 3,. so that even if there be aheavier portion of the shell on one side of the rib than on the other, no tilting 1n the bore will result.

The single rib arrangement thus lends itself to such shapes of projectiles, as shown in Fig. 3, where the long tapered portion K on one side of the rib F will overbalance the I much shorter portion L on the opposite side. 7

Where the shell is cylindrical, as shown in Fig. 1, then the two ribs H, I disposed at or near the ends are preferable. In case it is found desirable to support the shell body between the ribs H, I, then the intermediate rib J may be added; but it will be understood that it is preferable whether one rib small as possible while insuring proper positioning of the projectilein the bore.

We claim:

1. An elongated projectile shell for a smooth bore gun having on its periphery an integral surrounding rib symmetrically disposed with reference to. the weights of the portions of said shell on opposite sides of said rib.

2. An elongated projectile shell for a smooth bore gun consisting of two longitudinal interchangeable sections struck up from sheet metal and electrically welded at their registering edges, the said sections each including an integral semi-circular half rib, which ribs unitedly form a circular rib surrounding said rojectile and adapted to fit-the bore of sald gun.

In testimony whereof we have aflixed our signatures in presence of two witnesses.

THOMAS E. MURRAY, 'JR. JOSEPH B. MURRAY.

Witnesses:

GERTRUDE T. PORTER, MAY T. MQGARRY. 

